CONCHOLOGY. S87 
3. Genus Cleodora. Pl. IX. — 
Animal. Body oblong, gelatinous, contractile ; a head in front 
with two wings, and the posterior part enveloped in a shell, head 
distinct, projecting and round ; two eyes ; mouth in the form of a 
small beak ; destitute of tentacule ; two, opposite, membranaceous, 
pellucid, and cordated wings, placed at the base of the neck. 
Shell. Pyramidal, triangular, of a gelatinous or cartilaginous 
substance, very thin and transparent; aperture obliquely trun- 
cated. Inhabits the South American seas. Two species. 
Cleodora pyramidata. Cleodora caudata. 
4. Genus Limacina. Pl. IX. 
Animal. Body soft, oblong, two branchial fins situated at the 
base of the neck ; posterior part of the body spiral, and enveloped 
in a shell. ; 
Sheil. Thin, fragile, papyraceous, spiral, the whorls reunited 
in a planorbis form, and deeply and largely umbilicated on one 
side ; aperture large and entire. Inhabits the North seas. One 
species. 
Limacina helicialis. 
5. Genus Cymbulia. Pl. IX. 
Animal. Body oblong, gelatinous, pellucid, enclosing a shell ; 
- head sessile ; two eyes, and two retractile tentacula; mouth with 
a retractile proboscis ; two, opposite, oblong, ovate, branched wings, 
connate at their posterior base. 
Shell. Gelatinous, cartilaginous, very transparent, crystalline, 
oblong, in shape of a shoe, from which it has derived the name 
of the slipper, truncated at the summit.; aperture lateral and ante- 
rior. Inhabits the Mediterranean. One species. 
Cymbulia Peronii. 
6. Genus Preumodermon. Pl. IX. 
A molluscous animal, without any testaceous covering, and 
much resembling the genus Clio. Inhabits the Indian seas. One 
species. 
Pneumodermon Peronii. 
